Flexible pipe bending die



15, 1931. J w OFFUTT 1,837,060

FLEXIBLE PIPE BENDING DIE Filed April 29, 1930 3 Sheets-Sheet 1 Fig. 1.

IN VEN TOR,

ATTORNEYS.

Dec. 15, 1931'. w QFFUTT 1,837,060

FLEXIBLE PIPE BENDING DIE Filed April 29, 1930 3 Sheets-Sheet 2 h N ta /////v// f/%/% W V v S 1 I III 1 km T .m u n M ,7 m n m 1 l I i l I l I l I I N wig??? e A 4, w I w A H a Q r lfll m 2 1 l.|..l Q3 l S a Q k l nnv l u H a g m .3

2 ANN IN VEN TOR. J. W O/ H/TT W v M A TTORNEYS.

Dec. 15, 1931.

J. w. OFFUTT FLEXIBLE PIPE BENDING DIE :5 Shets-Sheet 3 Filed April 29, 1950 IN VEN TOR. J m/flffurr mwfwki ATTORNEYS;

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Patented Dec. 15, 1931 UNITED STATES P ATENTJ OFFICE JOHN W. OFFUTT, OF ELLWQOD CITY, PENNSYLVANIA, ASSIGNOR TO NATIONAL TUBE COMPANY, A CORPORATION OF NEW JERSEY FLEXIBLE PIPE BENDING DIE Application filed April 29,

This invention relates broadly to tube or pipe-bending machines and more. particularly to an improved form of bending die for such machines.

In existing machines known in the art, it is the practice to make the bending die and quadrant integral, the die having its face formed with a groove of a diameter substantially equal to the diameter of the tube to be This necessitates a quadrant for each radius of bend and for each diameter of tube.

The primary object of the present invention, therefore, is to generally improve and render more flexible machines of this class.

A further and more specific object is the provision of an improved type of die for tubebending machines which is readily adaptable to bends of varying radii, thus eliminating the necessity of removing and replacing dies for each radius of bend, with a resultant saving in time and labor.

Other objects and advantages resident in the improved machine will become apparent in view of the following description and 3 claims taken in connection with the drawings, wherein:

Figure 1 is a top plan View of a tube bending machine embodying the features of the invention, and

Fig. 2 is a view in sectional elevation taken on the line 22, Fig. 1.

3 is a detail plan viewof the improved bending die and cooperating mechanism, and Fig. 4 is a view in side elevation thereof.

Figs. 5 and 6 are, respectively, detail views in plan and elevation of parts of the die;

Fig. 7 is a fragmentary sectional view illustrating the mounting of the die in the quadrant; and i j Figs. 8 and 9 are similar views illustrating a means for adjusting the radius of the die.

Referring particularly to Figs. 1 and 2, the numeral 5 designates the base of the machine which supports the frame sections or castings 5a, 5b, 5c, and 5d.

The machine may be provided with any suitable type of drive mechanism, an example of which is illustrated in Fig. 2. The numeral 6 designates a drive shaft, which may be the armature shaft of a reversible motor, the

1920. Serial a... 442,301.

drive being transmitted by means of suitable reduction gearing to a shaft 7, having a worm 8 secured thereon, said worm meshing with a worm gear 9 which is preferably built up of an annular gear ring of bronze 'or the like bolted to a spider 9a, to reduce cost of construction, the hub 91) of the spider being keyed on a shaft 10 which extends vertically and is rotatably mounted in bearings 11 secured in the base and frame sections 5band 50.

' The upper extremity of the shaft 10 is shouldered and has keyed thereon blocks 12 and 12a, a bending quadrant 13 being secured to block 12. A vise or clamp, generally des' igjnated at 14, see Figs. 3 and 4, is secured to and rotates with the quadrant 18, said vise comprising jaws 14a and 1%, side rails or frame pieces 14c, cam 14d, screw 146, end block 14f, slide block 149 and block 14h, the block 14g being recessed to house a thrust block and the headed extremity of screw 140, which is retained in place by a plate 142', the said screw being threaded through block 14h and at its other extremity extending through the end block 14].

By turning the cam 1461, the vice jaw 14?) may be advanced or retracted, to thus grip and release the tube or pipe to be bent.

The tube or pipe to be bent, indicated at T in Fig. 1, is positioned in a follower l5 which is slidably mounted in a bracket support 16, the follower moving with the pipe when the bending die is caused to turn, to reduce friction and prevent damage to the tube, as will be understood. The support 16 is adj ustably maintained in position by a screw 17, which is threaded through a supporting bracket 18, said bracket being secured on supporting rails 19, provided with a plurality of securing holes 19a to enable adjustment of said bracket to varying'positions thereon. The lower extremity of the bracket 16 is recessed, to receive a thrust block and the headed end of screw 17, which is retained in said recess by a plate 21.

By adjusting the screw 17, the bracket 16 t and follower 15 may be advanced or retracted relatively to the bending die to compensate for adjustment of the radius of said die, and a further range of adjustment may be obtained by suitably positioning the bracket 18. An adjustable length rod 22 is connected at one extremity to the upper end of the shaft and at its opposite extremity said rod is passed through an extension 18a of the bracket 18, and adjustably retained in position by a thrust'block 22a and nut- 22'b, to relieve said shaft of extreme thrust when the bending die is in operation.

An essential feature of the present machine is the provision of What may be termed an articulated or jointed bending die, whereby the same die may be adapted for tube or pipe bends of a plurality of radii. This die consists of a plurality of segments 23, note Figs; 5 and 6, which are recessed on one face, so that when they are assembled, a continuous groove is provided for the tube or pipe to be bent, said segment beingbored at 23a to receive flexible rods 24, which are preferably of steehthese rods being secured at one extremity to the vise jaw14laand at their "opposite extremities provided with springs 25, whereby the die segments are maintained under tension. The segments 23 are shown *as having tapered sides, the taper beginning at an intermediate point, to facilitate radial adjustment when the segments are assembled on the rods 24. The rods 24 being flexible renders it possible to bend the die per se to practically any desired radius. Therefore, in order to secure the desired radius, all that is necessary is to provide a suitable backing for the segments 23.

Fig. 7 shows the articulated die applied directly on the flanged rim or periphery 13a of the quadrant 13, while Figs. 8 and 9 illustrate methods of backing up the die. The segments 23' are shown as secured in position by clamp blocks 2% which are bolted to the rim of the quadrant 13.

In Fig. 8 a filler 26 is illustrated as being secured on the face of the quadrant, to increase the radius of the die. Fig. 9 shows a number of shims or fillers 26a and 26?) added to the filler 26, illustrating how practically any desired radius may be obtained.

The operation of the machine will beobvious to those having a knowledge of the art. The tube or pipeto bebent is inserted in the follower and between the vise jaws 14a and 14b and adjusted to the desired position, the camlaal then being turned to clamp the tube in place.

The drive may then be applied by starting the motor or throwing a clutch, if suchbe installed, and the bending die and vise mechanism are caused to turn in the. direction indicated by the arrow in Fig. 1,'thus-bending the tube or pipe to the desired radius.

The cam 14d may then be turned to release the tube, which may be removed, and the drive thereafter reversed to return the bending quadrant and die and vise mechanism to their original-"position.

When a different radius of bend is desired, all that is necessary is to remove the die per se, comprising the segments 23 and flexible rods 24, and insert or remove fillers 26 and/or 27 and adjust the screw 17, and the machine is ready for operation.

It will be understood that theme'ans herein illustrated for backing up the die, or the fillers 26 and 27, are simply examples of numerous devices that may beadopted for this purpose, and may be varied at will without departing from the scope of the invention as defined by the appended claims.

What is claimed as new is:

1. In a pipe bending machine, the combination with a rotary bendingiquadrant, of air articulateddie on said quadrant, said die comprising a plurality ofsegments, said'segments being recessed on one face so that when they are assembled to form-said'die a continuous groove is provided for the pipe tobe bent, said segmentsbeing bored at spaced points in a-direction-parallel to the axis of the die, ible rods threaded through said bores, said rods'being anchored at one end to said quadrant'an-d having their-other ends projecting a material distance beyond said assembled segments forming saiddie, springs telescopically mounted on the projected ends of said rods, and'nut members threaded on the projected ends of said. rods and adapted to tension said springs against the endmost die segment whereby saidscgments are yieldably held in close contact with each other.

-2. In a pipe bending unachine, the combination with a rotary bendingquadrant, of an articulated die on said quadrant, said die comprising a'plur'ality of segments, said segments being recessed on one face so that when they are assembled to-form-said die-a continuous groove is provided for the pipe to be bent, said se ments being bored at spaced points in a direction parallel to the axis of the die, flexible rods threaded through said bores, said rods being anchored at one end to said quadrant and having their other" ends I projecting a material distance beyond said assembled segments forming-said die, springs telescopically mounted on the projected ends of said rods, means carried by said rods for tensioningsaid springs against the endmost die se mentwhereby said segments'are yieldably held in close contact with each other, and filler members adapted to be mounted between said quadrant and said die to vary the radius of the die, said filler-members being removably secured to=said quadrant.

In testimony whereof, I ha-ve'hereunto set my hand. 7

JOHN WV. OFFUTT. 

